Here's some random TSBS facts and lore I've learned over the years...
-Monty's original fate was going to be the destroyer of the old TSAMS dimension. (Golden Freddy reveals in one episode of the Monty and Foxy show that Monty was originally destined to destroy this reality but he moved some things around to prevent that fate from happening)
-Moon ate a man. (He was possessed by Killcode at the time. So while he technically didn't do it, it was his body)
-Sun used to cross-dress but most likely stopped cause of all the jokes Moon made about him.
-Lunar had a crush on Roxanne (He kept some of Sun's old pictures of her under his bed)
-Terra technically died (maybe. Sort of. It's still confusing. It was when she got jumped by BloodMoon in the original LAES)
Terra is the only Celestial family member to never swear. (She has cussed but nothing harder than "Well, that sucks.")
-Nexus was a Batman and MLP fan
-Roxas dated Chico, Happy Frog, Bonnie, and Clipsey (Roxas has an interesting list of exes)
-Castor is a fan of Red Dead Redemption much like Nebula
-Lolbit is an assassin
-Monty's sister Milly is a lawyer... and also an assassin. (Monty has an interesting family)
-Funtime Foxy accidentally proposed to Lolbit (He bent down to pick something up and Lolbit thought he was proposing and he just never corrected her)
-Toy Chica was a yandera (did I spell that right?) For Freddy back in high school. She has thankfully mellowed out.
Monty knows Walter White (That is not a joke)
Jack watches Helluva boss but only the episode Loo-Loo-land. (He likes Fizzarolli)
Hazbin Hotel and Helluva Boss do exist in the TSBS universe (Roxanne went to Hell and met Angel Dust. Does this mean HH and HB are reality shows in the TSBS universe?)
Spider-Verse exists here too. (Monty met a Spider-Man variant)
Golden Freddy hasn't told Glamrock Freddy what happened to Circus Baby, Roxanne, or Gregory (Why?! I don't know)
Glamrock Freddy and Roxanne dated through high school but broke up after Security Breach came out and Roxy got a big head from it.